Smokeless solid fuel heater with



Dec. 18, 1951 w, A, STUCKEY ETAL 2,579,213

- SMOKELESS SOLID FUEL HEATER WITH AIR cooLED CAST METAL SECONDARY AIR -CONDUT Filed Jan. 28, 1948 f 3 Sheets-Sheet 1 @www Dec. 18, 1951 W, A, STUCKEY E-l-AL 2,579,213

SMOKELESS SOLID FUEL HEATER WITH AIR COOLED CAST METAL SECONDARY AIR CONDUIT Filed Jan. 28, 1948 5 Sheets-Sheet 2 DCC- 148, 1951 w. A. s'rucKEY ETAL .2,579,213

SMOKELESS SOLID FUEL HEATER WITH AIR COOLED CAST METAL SECONDARY AIR CONDUIT Filed Jan. 28, 1948 5 Sheets-Sheet 3 Patented Dec. 18, 1951 SMOKELESS SOLID FUEL HATER WITH AIR-COOLED CAST METAL SECONDARY AIR CONDUIT Warren A. Stuckey, Matt Gregurich, and Frank Tomasich, Joliet,l Ill., assignorsto rllhe Conlon- Mocre Corporation, `oliet, il., a corporation of Illinois Application January 28, 1948, Serial No.4,798

1 claim. (c1. 126-76)A s The present invention relates generally to solid fuel heaters. More particularly the invention relates to that type of solid fuel heater which is known in the ar-t as a smokeless heater, serves as a space heating medium or instrumentality and as its principal components or parts com-` prises: (1) a vertically elongated, box-like shell having a normally closed air-tight ash pit or chamber in the lower portion thereof, a combination fuel and combustion chamber in its central portion, and a grate between the two chambers; 2) an outlet duct for the products of combustion leading upwards from aA point directly above the grate to a flue adjacent the top wall of the shell; (3) a duct arrangement opposite theV outlet duct for admitting outside primary air into the upper part of the combination fuel and combustion chamber andoutside primary air into the lowerrpart of such chamber; and (4) a horizontally extending conduit which is located 'directly inwards of the lower or inlet end of the outlet duct and is connected and arranged to deliver outside secondary air into the lower part-of the combination fuel and combustion chamber, f

It has heretofore been proposed in connection with the manufacture or fabrication of a smokeless solid fuelA heater of the aforementioned type to formthe secondary air conduit of cast metal and to provide in the lower portion of the conduit a single horizontal, full length discharge slot which faces inwards 'and downwards and serves to discharge the secondary air so that it iiows part way through the fuel in the lower part of the combination fuel and combustion chamber. In practice it has been found that a cast metal secondary air conduit is subject to the obr jection that during high capacity fuel consumptionof the heater the lower part thereof, i. e., the part having the single horizontal, full length downwardly and inwardly facing discharge slot, becomes heated to such an extent that it either burns out or warps. If the lower slot dening part of the secondary `air conduit burns out or warpsv to an appreciable extent the efliciency of the heater is pronouncedly reduced and itl is usually necessary to replace the conduit.

The primary object of the invention is to provide in connection with a smokeless solid fuel heater of the type and character under consideration simple means whereby the secondary air conduit is cooled to such an extent during heater operation that it does not burn out or warp and hence necessitatereplacement.

. Another objectv ofthe invention is to provide l 2 a smokeless solid fuel heater of thelast mentioned character wherein the cooling means for the secondary Iair conduit is in the form of an air passage arrangement which is disposed in. the lower part of the conduit and is adapted toA have outside air flow through vit in order to effectthe desired cooling of the conduit.

A further object of the invention is to provide a smokeless solid fuel heater which is generally of new and improved. construction and, due to its design and construction, possesses high eflciency and extremely long life.

Other objects ofthe invention and the various advantages and characteristics of the present fuel heater will be apparent from a consideration of the following detailed description.

The invention consists in the several novel features which lare hereinafter set forth and. are more particularly defined by the claim at the conclusion hereof.

In the drawings which accompany ,and form a part of this specification or disclosure andin which like numerals of reference denoteI corresponding parts throughout the several views:

Figure lr is a rear perspective view of a smokeless solid fuel heater embodyingthe invention;

Figure 2 is a vertical longitudinal section illustrating in' detail the construction, design and arrangement of the outlet duct, the primary air duct arrangement and the secondary air conduit.

Figure 3 is a vertical transverse section taken on'the line 3--3 of Figure 2 and showing in detail the air passage arrangement which is formed in the lower part of the secondary air conduit and serves in response to flow of outside air therethrough to effect cooling of such part of the conduit; and

Figure i is a horizontal section'on the line 4--4 of Figure 2. o y Y The smokeless ,heater which is shown in the drawings constitutes the preferred form or embodiment of the invention. It is designed for use as a space or room heater and may be red.

with bituminous coal, coke, anthracite coal, wood, or composition lfuel blocks. As its principal components or parts the heater comprises a shell lil, an outlet duct i I, a primary air duct arrangement l2, asecondary air conduit I3, and a grate I4. All of the parts, with the exception of the secondary air conduit I3, are of standard or.

' consists of a bottom wall I5, a front wall I6,

3 a back wall Il, a pair of side walls I8 and I9 and a top wall '20. The front wall I6 and the back wall I are arranged in opposed relation, and the side walls I8 and I9 extend between and at right angles to the front and back walls and have the side margins thereof suitably connected to the side margins of the last mentioned walls. The lower margins of the front, back and side walls are suitably secured to the marginal portions of the bottom wall. As shown in the drawings, the shell I is deeper than it is wide. In other words, it is elongated from front to back. The top wall 29 is rectangular and has its marginal portions suitably secured tothe upper marginal portions of the front, back and side walls of the shell. The lower portion of the shell interior constitutes an ash pit or chamber 2I and the central interior portion of the shell constitutes a combination fuel and combustion chamber 22. These two chambers are separated by the grate I4. The upper portion of the chamber 22 constitutes a space or magazine for the solid fuel and the lower portion of the chamber serves as a combustion space. A receptacle 23 for receiving and collecting ashes may, if desired, be positioned in the ash pit 2l beneath the grate I4. Access to the ash pit is provided by way of a rectangular opening 24 in the lower portion of the shell side wall I9. lThis opening is normally closed by an imperforate hinged door 25 and is suiciently Iwide to permit the receptacle 23 to be inserted into, and removed from, the ash pit Y dium for the products of combustion that result from burning of the solid fuel in the combustion space of the chamber 22. It embodies a vertically extending branch 28 along the central and upper portions of the front wall I6 of the shell and a horizontally extending branch 29 directly beneath the shell top wall 2B. The vertically extending branch of the outlet duct is defined by said central and upper portions of the front wall I6 together with the secondary air conduit I3 and a plate 30. The conduit I3 is spaced a comparatively small distance inwards from the central portion of the shell front wall I6 and extends between, and is secured to, the shell side walls I8 and I9, as hereinafter described more ink detail. VDuring operation of theheater the products of combustion travel horizontally over the grate 'I4 in the direction of the shell front wall I6 and then, after flowing under the secondary air conduit I3, passup-wards through the vertically extending branch 28 of the outlet duct II. The plate 30 is located for the most part above the conduit I3 and is disposed slightly inwards of, and in parallel relation with, the upper portion of the front wall I6 of the shell I0. The side margins of the plate 30 are bent at right angles to form anges which are suitably secured to adjacent portions of the shell side walls I8 and I9. The plate 3D defines with the adjacent portion of the shell front wall the upper end of the vertically extending rbranch 28 of the outlet duct II. The horizontally extending branch' 29 ofthe outlet duct is defined by the shell top wall '20 and a subjacent plate 3I. The latter is forwardly and downwardly inclined to a slight extent and defines the top of the combination fuel and combustion chamber 22. The front marginal portion of vthe plate 3i is secured to the upper marginal portion of the plate 30 -and the side marginal portions of the plate 3I are bent upwards at right angles to form anges which are suitably secured to the upper portions of the shell side walls I8 and i9. The rear end of the horizontallyextending branch '29 of the outlet duct II is connected to a i'iue 32 by way of a tubular nipple 33 on the upper portion of the shell back wall i1. When the heater is in operation the products of combustion, after flowing upwards through the vertically extending branch 28 of the outlet duct, now rearwards through the horizontally extending branch 29 and are then discharged to outside atmosphere by way of the iiue 32.

The duct arrangement I2 serves to admit primary air into the upper part of the combination fuel and combustion chamber 22 and primary air into the lowerpart of such chamber. It is disposed directly inwards of the back Wall I'I of the shell I6 and consists of an upwardly extending upper branch 34 and a downwardlyr and inwardly inclined lower branch 35. The upper branch 340i the duct arrangement I2 is defined by the upper portion of the shell back wall .I'I, a substantially vertically extending plate .36, and a horizontally extending partition forming plate 31. It has the upper end thereof open and in communication with the upper part of the fuel space of the chamber 22. The plate 36 is spaced inwards from the upper portion of the shell back wall and has its side margins suitably secured to the adjacent portions of the shell side walls I8 and i9. The upper margin `of the plate 36 is disposed a comparatively small distance below the plate 3|A in order' to effect communication between the upper end of the upper branch'34 of the duct I2 and the upper -part of therfuel space of the combination fuel and combustion chamber 22. The partition forming plate 31 is connected to, and extends outwardsfrom, the lowei marginal portion of the plate 36 and serves to divide or separate the upper and lower branches of the duct arrangement I2. The primary air that is supplied to the upper partV of the fuel space of the chamber 22 enters the lower end of the upper branch' 34 of the duct arrangement by way of a plate `valve controlled hole 38 in the central portion of the shell back wall Il. through the upper branch 34, flows downwards through the fuel in the chamber 22 and has a twofold purpose in that it prevents clogging of the fuel in the fuel space-of the chamber 22 and also serves, together with the primary air that is introducedY into such chamber by way of the lower branch 35, to promote combustion of the portion ofthe fuel that directly overlies the grate I4. The lower branch 35 of the duct arrangement I2 is defined or formed by a pair of spaced apart downwardly and inwardly inclined plates 39 and 46. f The plate 39 is located an appreciable distance beneath the partition forming plate 3l and extends downwards and inwards from the shell backfwall I'I. The side margins of the plate 39 are suitably secured to the adjacent portions of the sidewalls of the shell. The plate 4|] overlies the plate 39 and extends downwards and inwardsfrom the inner marginal portion of the partition forming plate The primary air, after flowing upwards 31. The. side .margins -ofl the plate -40 vare suitably secured to the .adjacent portions lof the shellside wallsand the lower marginal portion of said plate is spaced from the lower marginal portion of the plate 39 and .denes therewith a primary air 'outlet for the lower branch 35 of the yduct arrangement. As best shown in Figure .2 .such primary air outlet is .located ldirectly above Vthe grate I4 and serves tok cause the primary air passing therethrough to ow over the grate I4 in the direction of the lower endof the vertically extending branch 28 of. the `outlet 4duct Il. Primary air is introduced into the upper end of the vbranch by ,way of a plate valve controlled hole 4I in the back wall Il of the shell.

The conduit I3, which, as hereinbefore pointed out, assists in dening the lower end of the Vertically extending branch 28 ofV the outlet duct I I, is preferably in the form of a two-piece metal casting. It extends between the shell side walls I8 and I9 and consists of an outer piece 42 and a complemental inner piece 43. The outer piece 42 extends substantially vertically Iand has the upper marginal portion thereof rs ecured against the outer face of the lower marginalportion of the plate 363 by way of bolts or other suitable attaching devices (not shown). The central and lower portions of the cuter piece42 of*l the secondary air conduit are shaped to form a full length enlargement 44. The inner piece 43 of the conduit consists of a side wall 45, a top wall 4G, and a pair of end walls 4l. The side Wall 45 is disposed in opposed and spaced relation with the outer piece 42, and the top wall 46 is connected to, and projects outwards from, the outer marginal portion of the side wall 45 and has its outer marginal portion in abutment with the inner face of the lower margin-al portion of the plate 30 and secured thereto by the aforesaid bolts or other suitable attaching devices.

The end walls 4l extend -at right angles to the side and top walls 45 and 46 and abut against, and are suitably secured to, the adjacent portions of the shell side wlls I3 and I9. Secondary air is introduced into the manifold I3 from the space directly around the shell I0 of the heater by way of Circular holes 48 in the shell side walls I 8 and I9 and registering circular holes 49 in the upper portions of the end walls 41 of the inner piece 43 of the conduit. The lower part of the full length enlargement 44 of the outer piece 42 and the lower marginal portion of the side wall 45 of the inner conduit piece 43 are spaced apart and shaped so as to form a single horizontal, full length discharge slot 54 whereby the secondary air is introduced into the lower part of the combination fuel and combustion chamber 22. The slot 5U is inwardly and downwardly inclined and serves to discharge the secondary air so that it ows part way through the fuel in the lower portion of the combustion space of the chamber 22. The secondary air that is introduced by way of the slot 50 in the conduit I3 assists the primary air in effecting complete combustion to the end that the heater is smokeless. By reason of the fact that the products of combustion are at their highest temperature when they pass around the lower part of the secondary air conduit I3 the enlargement 44 at the lower marginal portion of the outer piece 42 of the conduit is subjected to extremely high heat conditions.

With the view of preventing burning out and warping of the lower part of the conduit the enlargement 44 is provided with a passage arrangement 5I whereby outside .air is permittedto. flow or circulate therethrough for cooling purposes. Asbest shown in Figure 3, rthe passage `arrangement 5I comprises a horizontally extending'lower branch 5Ia, a horizontally extending upper branch 5Ib and a vertically extending branch 5Ic. These three branches are formed in the full length enlargement 44 of the .outerpiece 42 of the secondary air conduit I3. The lower branch 51a is substantially cylindrical. It extends throughout the entire length of the aforesaid enlargement and has open ends which communicate with outside air by way of registering circular holes 52 inthe shell side walls I8 and I9. The horizontally extending upper branch -5lb of the passage arrangement overlies the lowel` branch Sla `and -extendsthroughout the entire length of thefenlargement 44 and has open ends which communicate with outsideair by way of registering holes 52a in the shell sidewalls I8 vand It. `Preferably the upper branchisv rectangular in `cross section. The vertically extending branch 5Icis located midway between the ends of the enlargement 44 and extends between, and serves .toy connect, the central yportions of the lower and upper branches Ela and SIb by way of the vertically extending branch 5Ic. After flowing into the central portion of the upper branch5lb the outside air ows. outwards through the end portions ofv the upper branch and is dschargedfto atmosphere via the holes A52a in the shell side walls.` The passage or circulation of air through the passage arrangement 5I is continuous and provides such cooling of the lower portion of the conduit that it, as well as the upper part, is effectively and eiiciently prevented from burning out or warping. The passage, in effect, provides for a continuous circulation of air and results in such reduction in temperature of the conduit that the latter possesses a life as great as that of the other parts of the heater and hence does not necessitate or require replacement.

The grate I4 is disposed between the ash pit 2| and the combination fuel and combustion chamber` 22 and consists of a rectangular frame 53, a pair of side by side grate bars 54 and a dump grate 55. The grate bars and dump grate are suitably supported by the frame so that they may be rocked back and forth in a manner well understood in the art.

The herein described smokeless solid fuel heater is highly efcient so far as operation is concerned. It possesses extremely long life by reason of the fact that the cast metal conduit I3 for supplying secondary air part way through the bed of Yfuel on the grate has associated with it effective and efficient cooling means whereby it is precluded from being heated to such a high degree as to cause burning out and warpage. The cooling means consisting of the air passage arrangement 5I is essentially simple in design and does not, to any appreciable extent, increase the cost of manufacture of the heater as a whole. It is self functioning or operating because it works on the natural draft principle and hence does not increase the cost of operation of the heater. By reason of the fact that the conduit has the air passage arrangement 5I it may be made of cast metal instead of cast refractory material.

The invention is not to be understood as restricted to the details set forth since these may be modified within the scope of the appended claim without departing from the spirit and scope of the invention.

Having thus described the invention what we air via holes in the shell, a horizontally extending upper branch with its ends open to outside air via holes in said shell and a vertically extending branch between, and in communication with. the

Y central portions of the upper and lower branches,

and adapted to have outside air by a natural ber and leading upwards from a point directly above the grate, and means within the shell and at the opposite side of the chamber for delivering primary air so that it ows in a wide stream over the grate in the, direction of the lower end of the outlet duct, said outlet duct forming means embodying at its lower end a horizontally elongated cast metal conduit disposed in laterally spaced relation with the primary air delivering means, having the ends thereof connected to receive outside air as secondary air, provided in the lower part thereof with a single horizontal full length discharge slot facing inwards and downwards and serving to discharge the secondary air towards the combustion space, and having on its lower and central parts and at the outer side of and above the slot a full length enlargement,

said enlargement having formed therein a pas-A sage arrangement closed to the shell and conduit interiors, consisting of a horizontally extending lower branch at the outer side of said slot and with the ends thereof open to outside draft action flow inwards through the open ends of the lower branch, then upwards through the vertically extending branch and then outwards to atmosphere via the open ends of the upper branch and thus elect cooling of the conduit during operation of the heater.

WARREN A. STUCKEY.

MATT GREGURICH.

FRANK TOMASICH,

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 552,911 Knauss Jan. 14, 1896 619,852 Washburn Feb. 21, 1899 1,152,363 Weisberger Aug. 3l, 1915 2,296,447 Lowe Sept. 22, 1942 2,403,829 Sanford et al. July 9, 1946 2,456,570 Stuckey et al. Dec. 14, 1948 FOREIGN PATENTS Number Country Date 138,608 Australia Aug. 25, 1934 

